Staff security engineer, application security

About WRITERWRITER is the AI platform built for the world’s most ambitious marketing and revenue teams, bringing the frontier of AI to the people who drive enterprise growth. With WRITER, autonomous agents work across the buyer journey, continuously executing on market signals and enterprise intelligence to grow revenue faster. Every agent action and asset is grounded in trust, built on an Enterprise Brain that unites brand, product, and company knowledge with fiduciary-grade governance and compliance. Fortune 500 companies are transforming how they go to market with WRITER, including 3 of the top 5 US banks, 2 of the 5 largest global CPG conglomerates, and 4 of the top 5 US healthcare insurers. Founded in 2020, WRITER is backed by investors including Insight Partners, ICONIQ, Radical Ventures, Premji Invest, Balderton, B Capital, Salesforce Ventures, Adobe Ventures, Accenture, Citi Ventures, IBM Ventures, WndrCo, and others. Learn more at WRITER.com. About the roleThis is where security meets innovation at enterprise scale. As a staff security engineer, applications at WRITER, you'll be building the security foundations that protect the AI systems powering some of the world's most recognizable brands. You'll work at the intersection of application security, AI infrastructure, and developer enablement—partnering with engineering teams to embed security into every line of code while ensuring our platform remains both powerful and trustworthy.The opportunity is massive: you'll help define how enterprise AI applications are secured, from threat modeling our LLM architectures to building automated security controls that scale across our growing platform. This isn't about saying "no"—it's about finding creative ways to say "yes, and here's how we do it securely." You'll tackle challenges that most security engineers never encounter: securing AI agents, protecting training data pipelines, and designing controls for systems that didn't exist a few years ago.This role is hybrid from our New York City, San Francisco, or Seattle offices, reporting to the head of security engineering.‍️ What you'll doBuild security into the DNA of our AI platform by conducting threat modeling sessions with product teams, designing secure architectures for new features, and ensuring security considerations shape product decisions from day one—not after the factOwn and evolve our application security program including establish and maintain SAST/DAST scanning in CI/CD pipelines, conducting security code reviews for critical changes, and building automation that catches vulnerabilities before they reach productionPartner with engineering teams to establish and champion secure coding standards, creating reusable security patterns and libraries that make it easier for developers to build securely by defaultDesign and recommend security features and products that help secure customer environments. You are the advocate and the vision for how we protect and secure customers..Integrate and leverage AI agents to help increase velocity for the security team and the overarching engineering org to ensure that we are proactive in minimizing risk while we build productsLead security assessments and penetration testing of WRITER's applications, AI services, and APIs, identifying vulnerabilities across our tech stack and working collaboratively with teams to remediate issues at scaleDesign and implement security controls for protecting data pipelines, model training environments, and customer-facing AI agentsStay ahead of emerging threats in the AI/ML security landscape, researching attack vectors specific to LLMs and generative AI, and proactively building defenses against novel risks️ What you needMinimum 4 years of hands-on experience in application security engineering, with a proven track record of securing large-scale production systems—bonus points if you've worked in fast-growing startups or high-growth environmentsUnderstanding of developer experience and developer workflows for shipping features and products. You care deeply about reducing risk while considering velocity of engineers.Technical expertise in at least two programming languages (Python, Java, Go, JavaScript/TypeScript) and the ability to read and review code across multiple languages, understanding both business logic and security implicationsKnowledge of security tools and methodologies including SAST/DAST solutions, vulnerability management platforms, security testing frameworks, and DevSecOps practices—you know which tools to use and when automation beats manual reviewExcellent communication skills that allow you to translate complex security concepts into clear recommendations for both technical and non-technical audiences—you can explain why something matters and motivate teams to actionA builder's mindset that looks for opportunities to automate, scale, and empower rather than create bottlenecks—you understand that security enables the business, not blocks itAlignment with WRITER's values of Connect (building strong relationships across teams), Challenge (pushing the boundaries of what's possible in AI security), and Own (taking end-to-end responsibility for the security of our platform)*This role is open to Mid, Sr. and Staff level candidates Benefits & perks (US Full-time employees)Generous PTO, plus company holidaysMedical, dental, and vision coverage for you and your familyPaid parental leave for all parents (16 weeks)Fertility and family planning supportEarly-detection cancer testing through GalleriFlexible spending account and dependent FSA optionsHealth savings account for eligible plans with company contributionAnnual work-life stipends for:Wellness stipend for gym, massage/chiropractor, personal training, etc.Learning and development stipendCompany-wide off-sites and team off-sitesCompetitive compensation, company stock options and 401kWRITER is an equal-opportunity employer and is committed to diversity. We don't make hiring or employment decisions based on race, color, religion, creed, gender, national origin, age, disability, veteran status, marital status, pregnancy, sex, gender expression or identity, sexual orientation, citizenship, or any other basis protected by applicable local, state or federal law. Under the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.By submitting your application on the application page, you acknowledge and agree to WRITER's Global Candidate Privacy Notice.Compensation Range: $183K - $240KLocationNew York City, NY; San Francisco, CA; Seattle, WAEmployment TypeFull timeLocation TypeHybridDepartmentEngineering, product & designCompensationSF & NYCBase Compensation $204K – $240K • Offers EquityOther US LocationsBase Compensation $183K – $216K • Offers EquityWRITER is committed to transparent, market-based compensation practices. Compensation offered will be determined by multiple factors such as role scope and complexity, location, experience, knowledge, and skills. Cash compensation is only one part of WRITER’s competitive Total Rewards package, which can also include equity, an immersive purpose-driven culture, career development, and thoughtfully designed benefits and well-being offerings.